There is known a supporting device (a suspension device) that supports a projector, which modulates and projects light, and enables the projector to be set on a wall surface, a ceiling, or the like (see, for example, PTL 1). Such a supporting device includes an adjusting mechanism for adjusting a supporting state (the position, the tilt, etc.) of the projector. A user can adjust (correct) the position, the size, the shape, and the like of a displayed image by operating the adjusting mechanism.